1. Field of the Invention
The present invention relates to a vehicle lamp that uses, as a light source thereof, a special LED or a custom LED which is different from an ordinary LED.
2. Prior Art
A lamp structure that employs LEDs (light emitting diodes) is often adopted for vehicle lamps such as high-mount stop lamps and the like.
In such a vehicle lamp that uses LEDs, as shown in FIG. 8, the light from an LED 112 is subjected to a diffusion deflection control by a plurality of lens elements 114s formed on a front lens 114 provided in front of the LED 112. However, since the LED 112 emits only a small amount of light, it is difficult to produce a sufficient amount of illumination light for a vehicle lamp.
More specifically, as seen from FIG. 8, in an ordinary LED 112, of the light radiated from an LED chip 122 that is embedded in a bullet-shaped translucent body 124, the radiation light within a predetermined range of angle with respect to the forward direction of the lamp is used by way of rendering it to be refracted toward the front with the use of a substantially semi-spherical condenser lens 126 that forms the front end portion of the translucent body 124. However, the light radiated at a great radiation angle with respect to the forward direction becomes stray light and therefore cannot be used for illumination. Accordingly, a vehicle lamp that incorporates the LED 112 as described above cannot easily provide a sufficient amount of illumination light
The alternative is a method in which, instead of an ordinary LED, a special LED 12 as shown in FIG. 7 is used as a light source of a vehicle lamp.
In this special LED 12, of the light radiated from an LED chip 22 embedded in a translucent block body 24, the radiation light within a predetermined range of angle with respect to the forward direction is used, as in an ordinary LED, by way of rendering it to be refracted toward the front with the use of a condenser lens 26 that is formed to protrude in a substantially semi-spherical shape from the front end surface 24a of the translucent block body 24. As to the light radiated at a great radiation angle with respect to the forward direction, such is used also by reflecting the light by a portion of the front end surface 24a of the translucent block body 24 that is an area around the condenser lens 26 and then reflecting it by a reflector 28 provided inside the translucent block body 24.
With the use of the special LED 12, the utilization efficiency of the light radiating from the LED chip 22 increases, and as a result, the amount of light emitted increases also. It becomes thus possible to provide a sufficient illumination light intensity required for vehicle lamps.
However, a mere disposing of a front lens in front of the special LED 12 causes problems.
More specifically, in FIG. 7, the direct light B1 passing through the condenser lens 26 does not form a bundle of parallel rays, and it forms a bundle of diffused rays. Accordingly, the direct light B1 starts to intersect with the reflection light B2, which is from the reflector 28, at a position Po that is some distant in front of the special LED 12.
As a result, when the front lens is disposed at a position Pf that is greatly apart from the special LED 12, the front lens has an overlapped incidence area where the overlapped direct light B1 and reflection light B2 are incident. Therefore, in the overlapped incidence area, the direct light B1 and the reflection light B2 are inevitably subjected to the same diffusion deflection control. However, the direct light B1 and the reflection light B2 have different directions of incidence on the front lens, and the direct light B1 has a greater luminous intensity than the reflection light B2. Thus, the problem is that a diffusion deflection control on light from the special LED 12 by means of the front lens cannot be done appropriately.
Conversely, if the front lens is disposed at a position Pn that is closer to the special LED 12, the direct light B1 and the reflection light B2 impinge on the front lens without any intersection, so that the front lens has a no-light impinging area where no light from the special LED 12 is incident. The no-light impinging area appears as a ring-shaped dark area when the lamp is on. Thus, the problem is that the appearance of the lamp is degraded.
Accordingly, the present invention is to solve the problems described above.
It is an object of the present invention to provide a vehicle lamp that includes a special LED or a custom LED wherein the lamp is capable of appropriately performing diffusion deflection control on the light from the special LED by means of a front lens without degrading the appearance of the lamp.
The present invention achieves the object by contriving the layout of a front lens.
More specifically, the above object is accomplished by a unique structure of the present invention for a vehicle lamp that includes a special LED, which is a light source, and a front lens, which is provided in front of the special LED and performs a diffusion deflection control of light from the special LED by a plurality of lens elements formed on the front lens; and in the present invention,
the special LED is comprised of a translucent block body, an LED chip embedded in the translucent block body, a condenser lens protruded in a substantially semi-spherical shape on the front end surface of the translucent block body and positioned in front of the LED chip, and a reflector provided inside the translucent block body so as to forwardly reflect the light originated by the LED chip and reflected by a portion of the front end surface of the translucent block body that is a peripheral area of the condenser lens; and
the front lens is disposed near a position where the direct light from the LED chip and passing through the condenser lens and a reflection light reflected by the reflector start to intersect with each other.
The front lens can take any structure in terms of layout and shape of each lens element formed thereon as long as the front lens is designed so that the light from the special LED is subjected to a diffusion deflection control by the lens elements.
Each lens element can be a lens element that merely has a function of diffusing incident light or be a lens element that merely has a function of deflecting the incident light. Furthermore, it can be a lens element that has functions to diffuse and deflect the incident light.
In the vehicle lamp of the present invention, the special LED, which is the light source, is comprised of a translucent block body, an LED chip embedded in the translucent block body, a condenser lens protruded in a substantially semi-spherical shape on the front end surface of the translucent block body and positioned in front of the LED chip, and a reflector provided inside the translucent block body so as to forwardly reflect the light originated by the LED chip and reflected by a portion of the front end surface of the translucent block body that is an area around the condenser lens. Accordingly, the light irradiated from the LED chip in directions within a predetermined range of angle with respect to the front of the LED chip is refracted toward the front by the condenser lens and can be used for illumination, and in addition the light radiating at great radiation angles with respect to the forward direction can be also used as reflection light from the reflector. Accordingly, the use efficiency of the radiation light from the LED chip is improved, and the amount of light emitted is increased. Consequently, the lamp sufficiently provides an amount of illumination light required for a vehicle.
In the vehicle lamp of the present invention, the light from the special LED is subjected to a diffusion deflection control by a plurality of lens elements of the front lens provided in front of the special LED. Since the front lens is disposed near the position where the direct light passing through the condenser lens and the reflection light from the reflector start to intersect with each other, the lamp has various advantages.
Though the direct light and the reflection light differ from each other in the direction of incidence and the intensity, since the front lens is disposed near the position at which the direct light and the reflection light start to intersect with each other, the formation of an overlapped incidence area in the front lens where the overlapped direct and reflection lights is incident is avoided. Thus, it is possible to appropriately perform the diffusion deflection control on the light from the special LED by means of the front lens.
Furthermore, since the front lens is disposed near the position where the direct light and the reflection light start to intersect with each other, the formation of a ring-shaped no-light impinging area in the front lens where no light from the special LED is incident is prevented. Thus, the front lens appears bright over the entire surface when the lamp is on, and appearance degradation of the lamp is prevented.
As seen from the above, according to the present invention, a vehicle lamp that includes a special LED appropriately performs a diffusion deflection control on the light that is from the special LED by means of the front lens without causing any degradation in the appearance of the lamp.
In the meantime, as described above, the direct light passing through the condenser lens has a higher light intensity than the reflection light from the reflector. Therefore, if, of the plurality of lens elements that form the front lens, a lens element positioned in a direct light impinging area where the direct light impinges has a diffusion angle that is set at a value which is greater than a diffusion angle of a lens element positioned in a reflection light impinging area where the reflection light impinges, then the entire front lens appears substantially uniformly bright when the lamp is on. The appearance of the lamp is thus enhanced.
Meanwhile, the borderline between the direct light impinging area and the reflection light impinging area appears in a substantially circular shape on the front lens. Accordingly, if a plurality of lens elements are disposed in a grid pattern, some of the lens elements are positioned on the borderline between the direct light impinging area and the reflection light impinging area. In such a structure, by way of setting the diffusion angle of each lens element positioned on the border line at a diffusion angle that is set for the lens element of the two areas that correspond to one of the direct light and the reflection light that impinges in a greater amount, it becomes possible to perform a sufficiently appropriate diffusion deflection control.
The vehicle lamp of the present invention uses either a single special LED or a plurality of special LEDs as a light source.
When a plurality of special LEDs are employed, they are disposed so as to have an aligned irradiation direction. In this structure that uses a plurality of special LEDs, the front lens includes a plurality of lens elements that perform, for each one of the special LEDs, the diffusion deflection control on the light from the special LEDs. Thus, the front lens appears bright for a broad luminescent area.
Furthermore, it can be designed so that a plurality of special LEDs are disposed in a row and each special LED has a substantially rectangular shape that is elongated in the direction of the row or linear arrangement of the LEDs. With this structure, a thin-type lamp structure suitable for a high-mount stop lamp or the like can easily be produced.